Crypto.Hash.MD5

A module containing MD5 bindings

Incremental API

This API is based on 4 different functions, similar to the lowlevel operations of a typical hash:

• init: create a new hash context
• update: update non-destructively a new hash context with a strict bytestring
• updates: same as update, except that it takes a list of strict bytestrings
• finalize: finalize the context and returns a digest bytestring.

all those operations are completely pure, and instead of changing the context as usual in others language, it re-allocates a new context each time.

Example:

import qualified Data.ByteString
import qualified Crypto.Hash.MD5 as MD5

main = print digest
  where
    digest = MD5.finalize ctx
    ctx    = foldl MD5.update ctx0 (map Data.ByteString.pack [ [1,2,3], [4,5,6] ])
    ctx0   = MD5.init

newtype Ctx

MD5 Context

The context data is exactly 88 bytes long, however the data in the context is stored in host-endianness.

The context data is made up of

• a Word64 representing the number of bytes already feed to hash algorithm so far,
• a 64-element Word8 buffer holding partial input-chunks, and finally
• a 4-element Word32 array holding the current work-in-progress digest-value.

Consequently, a MD5 digest as produced by hash, hashlazy, or finalize is 16 bytes long.

Constructors

Ctx ByteString

init :: Ctx

create a new hash context

update :: Ctx -> ByteString -> Ctx

update a context with a bytestring

updates :: Ctx -> [ByteString] -> Ctx

updates a context with multiple bytestrings

finalize :: Ctx -> ByteString

finalize the context into a digest bytestring (16 bytes)

Single Pass API

This API use the incremental API under the hood to provide the common all-in-one operations to create digests out of a ByteString and lazy ByteString.

• hash: create a digest (init + update + finalize) from a strict ByteString
• hashlazy: create a digest (init + update + finalize) from a lazy ByteString

Example:

import qualified Data.ByteString
import qualified Crypto.Hash.MD5 as MD5

main = print $ MD5.hash (Data.ByteString.pack [0..255])

NOTE: The returned digest is a binary ByteString. For converting to a base16/hex encoded digest the base16-bytestring package is recommended.

hash :: ByteString -> ByteString

hash a strict bytestring into a digest bytestring (16 bytes)

hashlazy :: ByteString -> ByteString

hash a lazy bytestring into a digest bytestring (16 bytes)

HMAC-MD5

RFC2104-compatible HMAC-MD5 digests

hmac

Arguments

:: ByteString

secret

-> ByteString

message

-> ByteString

Compute 16-byte RFC2104-compatible HMAC-Md5 digest for a strict bytestring message

Since: 0.11.100.0

hmaclazy

Arguments

:: ByteString

secret

-> ByteString

message

-> ByteString

Compute 16-byte RFC2104-compatible HMAC-MD5 digest for a lazy bytestring message

Since: 0.11.100.0